Characterization and Treatability of
Selected Shellfish Processing Wastes
CHARLES R. HORN, Engineer
Alabama Water Improvement Commission
Montgomery, Alabama 36104
FREDERICK G. POHLAND, Professor
School of Civil Engineering
Georgia Institute of Technology
Atlanta, Georgia 30332
INTRODUCTION
The shellfish processing industry in the southern United States is primarily located in
picturesque coastal communities served by estuarine bayous and rivers. Suggestive in
appearance of the seafaring legend and tradition borne out by names like Bayou La Batre,
Bayou Coden, and Bon Secour, these communities are occupied largely by families having a
lengthy heritage as fishermen and seamen, by low income processing plant workers, and
by financially secure owners of trawlers and processing plants.
The shellfish processing industry includes shrimp processing, the larger of the Gulf
Coast and Lower Atlantic seafood industries, crab processing, and oyster processing; each
producing a high value product from two of the world's most prolific fisheries. Gulf Coast
fisheries embrace an area from Tampa, Florida to the Mexican border in Texas including
coastal waters out to 50 miles. Fishing grounds tend to be scattered with a general
concentration around Louisiana, the center of production. South Atlantic fisheries extend
from the Carolinas down to Florida with processing plant concentrations in Georgia and
South Carolina.
The shellfish processing industry is one of the industries to become more recently
subjected to pollution controls imposed by regulatory authorities. With the exception of a
few major shrimp processors, this is a consequence of the discharge of processing wastes
into tidal rivers, inlets, and bayous and the benefits of the flushing effect provided by tidal
action, as well as the proximity of major industries which often have a much more dramatic
impact on the receiving water.
SHRIMP PROCESSING INDUSTRY
Processing Operations
Shrimp are caught commercially with otter trawls which drag the floor of the fishery
with weighted nets. The catch is brought aboard, the "trash" fish discarded, and the shrimp
packed in ice in the hold. Re-icing may be necessary if the return exceeds 12 hours. Some
trawlers may land their catches at distant ports for transfer to trucks for more expedient
delivery to the processor (1).
Shrimp processing plants can be classified by the type processing performed. A typical
flow diagram is illustrated in Figure 1. The simplest of the processing operations is that of
the packing plant which receives the shrimp either whole or deheaded, deheads them if
necessary, weighs the catch and packs it in ice for shipment to another processor for
breading, freezing or canning. At quick-freeze plants the deheaded shrimp received from
the packers, are graded, thawed, peeled, and deveined prior to quick-freezing. The brittle
finished product is packaged and stored in blast freezers for shipment.
Breading is applied following the thawing, grading, and peeling and deveining
sequence; the latter being performed either mechanically or manually for custom processed
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